Appliance to be implanted, method of collapsing the appliance to be implanted and method of using the appliance to be implanted

ABSTRACT

A collapsible artificial blood vessel A comprises a flexible front end wire ring 101, a flexible rear end wire ring 102 arranged facing to the front end wire ring, a tubular cover 7 which connects the end wire rings, and a plurality of intermediate wire rings 12 arranged spaced apart from each other between the front end wire ring and the rear end wire ring. The circumference of the front end wire ring is equally divided into four segments by dividing points 411, 421, 431, 441. Hooks 13 are formed for a front pull string to be passed through at the dividing points 411, 431. The circumference of the intermediate wire rings are fixed to the tubular cover 7 by suturing or with adhesive at the positions 513, 523, 533 and 543. The device is collapsed for use by folding the wire rings and insertion of the device into a funnel tube.

This application is a divisional of application Ser. No. 08/765,216,filed Jan. 3, 1997 now U.S. Pat. No. 5,843,162.

FIELD OF THE ART

This invention relates to appliances for medical treatment and, moreparticularly, to an appliance collapsible for insertion into a humanorgan and capable of resilient restoration (which will be referred to as"the appliance to be implanted" in this specification and claims), to amethod of collapsing the appliance to be implanted, and to a method ofusing the collapsed appliance to be implanted into a catheter.

BACKGROUND ART

The artificial blood vessel is an example of the appliance to beimplanted. At present, treatment of, for example, aortic aneurysm isconducted by implanting an artificial blood vessel. In particular, theportion of a blood vessel which has an aneurysm is removed by resection,and an artificial blood vessel is implanted in place of the resectedportion and connected to the remaining blood vessel by suturing or thelike.

The above-mentioned method of surgically implanting the artificial bloodvessel for treatment of aortic aneurysm, however, is highly dangerous.Especially, an emergency operation for treatment of a ruptured aneurysmhas a low life-saving rate, and an operation of dissecting aorticaneurysm is difficult to conduct and has a high death rate.

Therefore, in order to treat these diseases without a surgicaloperation, a method has been developed of introducing a catheter into anappliance such as an artificial blood vessel in collapsed condition intoa human organ such as a blood vessel, and transporting the appliance toa desired position such as an affected or constricted portion thereof,where the appliance is released so as to be expanded and implantedthere.

The appliance to be implanted is so constructed that a pair of end wirerings which are flexibly foldable and elastic are arranged to dividethemselves, each of the end wire rings is connected by a tubular coverwhich is made of a sheet of flexible and tensile material and anintermediate wire ring is arranged between both of the end wire ringsand fixedly connected to the above-mentioned tubular cover by suturingor with adhesive.

As a method of collapsing the appliance to be implanted, the followingmethod is adopted in which a plurality of hooking means for a pullstring to be passed are formed at every other dividing points each ofwhich equally divides the circumference of the front end wire ring intoan even number, the front end wire ring is folded into a wavy shape withthe dividing points which are provided with a hooking means for a pullstring forming forwardly directed peaks and the dividing points whichare not provided with a hooking means for a pull string forming thebottoms of forwardly directed valleys, each of the intermediate wirerings and the rear end wire ring is folded into a wavy shape having thesame phase as that of the front end wire ring and the whole artificialblood vessel is inserted into a catheter.

The above-mentioned intermediate wire ring is inevitable because ofseveral points of view, such as it provides the artificial blood vesselwith a capability of keeping its tubular shape so as to fit a human bodywhen arranged at a bent position in a body, thereby to prevent theartificial blood vessel from being pushed downstream. However, if suchan intermediate wire ring is attached to the tubular cover, theappliance is easily prevented from being folded. The reason is that thetubular cover tries to follow the movement of the front end wire ringwith forming big wrinkles near the front end wire ring when the frontend wire ring is folded into a wavy shape since the tubular cover isconnected to the front and rear end wire rings at both end portionsthereof. However, as the tubular cover is made of a sheet, the locallyformed wrinkles do not bring about transformations at the center of thetubular cover. Therefore, for example, if the whole area of thecircumference of the intermediate wire ring is fixedly connected to thetubular cover, the center of the tubular cover is dragged at thespecified positions of the circumference thereof toward the direction ofthe peak or the valley along the wavy shape of the intermediate wirering and the whole tubular cover tends to be bulky as well asunfavorable load is applied to the intermediate wire ring because of thesliding resistance. Therefore, the intermediate wire ring may behindered from being folded into a small size with forming a regular wavyform because of distortion of the direction the intermediate wire ringis to be folded as well as of folding force. Even though theintermediate wire ring is fixedly connected to the tubular cover only atseveral points of the circumference thereof each of which is spacedapart, the points selected at random will cause sliding resistance fromthe tubular cover toward the peaks or valleys, thereby to provide noeffective means to solve the problems.

In addition, the mutual interference between the intermediate wire ringand the tubular cover not only prevents the intermediate wire ring frombeing folded but also folds the appliance to be implanted imperfectlyand insufficiently. Bent portion caused by the appliance to be implantedunnaturally folded will cut off the permanent function as a bloodvessel. This also may hinder the movement of transporting the artificialblood vessel through a catheter and the function of the appliance to beimplanted as it is intended to because of imperfect restoration of theappliance to be implanted even though the appliance to be implanted isreleased at a target portion.

On the other hand, the blood vessel is distributed variously in a bodyand, for example, an artery which comes from a heart is bifurcated atthe groin of a thigh. If an affected part falls on the bifurcated part,the above mentioned cylindrical-shaped artificial blood vessel can notbe used as it is, so that it is inevitable that an artificial bloodvessel whose shape fits for such a shape of blood vessel should bedeveloped. In addition, for implanting an artificial blood vessel insuch a bifurcated part it is not enough just to transport the artificialblood vessel to a target position through a catheter and release itthere. In this case, it is necessary to move the artificial blood vesselto be fit for a shape of the blood vessel at an target position afterreleased, thereby requiring to develop a method of moving the artificialblood vessel.

The object of the invention is to solve all of the above-mentionedproblems.

DISCLOSURE OF THE INVENTION

The appliance to be implanted in accordance with the invention ischaracterized by that comprising a front end wire ring, a rear end wirering arranged facing to the front end wire ring, a tubular cover whichconnects the front end wire ring and the rear end wire ring, and aplurality of intermediate wire rings spaced apart from each otherbetween the front end wire ring and the rear end wire ring, that each ofthe front end wire ring and the rear end wire ring and the intermediatewire rings are given flexibly foldable elasticity, that thecircumference of the front end wire ring is equally divided into four oran even number over four, hooking means are formed for a front pullstring to be passed through at every other dividing point and that thecircumference of the intermediate wire ring is fixed to the tubularcover by suturing or with adhesive at the positions which correspond tothe midpoints between each adjacent two of the dividing points of thefront end wire ring.

The appliance to be implanted may concretely be represented by that asingle rear end wire ring is arranged to face to a single front end wirering, or that parallely arranged two rear end wire rings are arranged toface to a single front end wire ring and a bifurcated tubular coverconnects the front end wire ring and two rear end wire rings withforming a Y-shape.

To improve the implanting state of the appliance to be implanted, it iseffective that each of the front and rear end wire rings iscircumferentially covered with an elastic protective material, thornsare provided on the circumference of at least one of the wire rings soas to stick into a human organ to be embedded therein, or a pole isprovided to connect at least two adjacent wire rings.

The method of collapsing the appliance to be implanted in accordancewith the invention is characterized by that the appliance to beimplanted comprises a front end wire ring, a rear end wire ring arrangedfacing to the front end wire ring, a tubular cover which connects thefront end wire ring and the rear end wire ring, and a plurality ofintermediate wire rings spaced apart from each other between the frontend wire ring and the rear end wire ring, that each of the front andrear end wire rings and the intermediate wire rings are given flexiblyfoldable elasticity, that the circumference of the front end wire ringis equally divided into four or an even number over four, hooking meansare formed for a front pull string to be passed through at every otherdividing point and that the circumference of the intermediate wire ringis fixed to the tubular cover by suturing or with adhesive at thepositions which correspond to the midpoints between each adjacent two ofthe dividing points of the front end wire ring, and that the methodcomprises the steps of; folding the front end wire ring into a wavyshape with the dividing points each of which is provided with a hookingmeans forming forwardly directed peaks and the other dividing pointsforming the bottoms of forwardly directed valleys, and folding theintermediate wire rings and the rear end wire ring each into a way shapehaving the same phase as that of the front end wire ring, thereby toinsert the whole appliance to be implanted into a catheter.

If the number of the dividing points are four, it is effective to pickthe whole appliance to be implanted by forceps along a generatrix whichpasses two points facing each other on the front end wire ring and eachof which is provided with a hooking means and then to insert theappliance to be implanted together with the forceps into the funneledtube from a big portion of the funneled tube toward a small portionthereof, and finally to pull the forceps out of the funneled tube.

The forceps may preferably be provided with serrate engaging memberwhich lessens a sliding resistance between the appliance to be implantedand the forceps toward the direction to be pulled than that to beinserted.

For inserting an appliance to be implanted which has been kept in acollapsed condition into a catheter, it is effective that a pair ofstrings each of which has a loop at the tip thereof are provided foreach of the wire rings respectively, that the strings are engaged witheither one of the wire ring or the tubular cover at the positions of thecircumference of each wire rings which correspond to the midpointsbetween two adjacent dividing points of the front end wire ring, and oneof the strings is wound around the wire ring clockwise until it reachesthe backward of the wire ring while the other string is wound around thewire ring counterclockwise until it reaches the backward of the wirering, that a retaining rod is passed through the part at which each ofthe loops overlaps, and that each of the strings is tied each other soas to keep each of the wire rings in a collapsed condition. Theretaining rod may preferably comprise a tube and a wire which isinserted into and passed through the tube. It is especially advantageousthat after the wire rings are kept in a collapsed condition, the tube ispulled out so as to keep the collapsed condition by the wire alone.

For collapsing each wire rings into a wavy shape by inserting theappliance to be implanted into a funneled tube from a big portion of thefunneled tube toward a small portion thereof, it is effective theappliance has previously been contained in a pipe member having adiameter which is bigger than that of the small portion of the funneledtube and smaller than that of the big portion of the funneled tube.

The method of using the appliance to be implanted in accordance with theinvention is characterized by that the appliance to be implantedcomprises a single front end wire ring, parallely arranged two rear endwire rings facing to the front end wire ring, and a Y-shaped tubularcover connecting the front end wire ring and the rear end wire rings, inorder to implant the appliance to be implanted into a Y-shaped portionhaving two branches bifurcated from a single trunk a front hooking meansis formed at the front end wire ring for pulling whole of the applianceto be implanted forward and a rear hooking means is formed at each ofthe rear end wire rings for pulling the appliance to be implantedrearward respectively, and that the method comprises the steps of;pulling the front hooking means of the front end wire ring toward thetarget portion to be implanted so as to transport the appliance to beimplanted through one of the branches to the trunk, and then pullingeach of two rear hooking means of the rear end wire rings so as to drageach of the rear end wire rings to one of the branches and to the otherbranch respectively.

For inserting one of the rear hooking means of the appliance to beimplanted into one of the branches of a Y-shaped portion to be implantedand dragging it into other branch thereof, it is effective that a devicefor transporting an appliance to be implanted is attached to the rearhooking means of the appliance to be implanted so as to urge theappliance to be implanted rearward when the appliance to be implanted istransported to near the trunk through one of the branches and that thedevice for transporting an appliance which is attached to one of therear hooking means of the appliance to be implanted is caught anddragged into other branch by a catcher which has been inserted into nearthe trunk through other branch.

For securely catching the device for transporting an appliance by acatcher, it is preferable that the device for transporting an applianceto be implanted which is to be dragged out of the body by a catcher istransported to a portion to be implanted through one of the brancheswith the front end of the device engaged with the rear hooking means,that the base end of the device is turned down and transported to theportion to be implanted through the same branch, and then the base endof the device is caught by the catcher.

For effectively preventing the device for transporting an appliance tobe implanted from entangling in the appliance to be implanted, it ispreferable to adopt a method that comprises steps of; arranging a guidepipe which has a valve at the base end thereof along one of the branchesand into which the front end of the device for transporting an appliancehas previously been inserted through a hole provided on the valve bybeing pushed to open the hole with making use of the elasticity of thehole, pushing the base end of the device for transporting an appliancewhich is turned down so as to be inserted into the guide pipe throughother hole provided on the valve so as to open the hole with resistingthe elasticity of the hole, and pulling the catcher which catches thebase end of the device for transporting an appliance so that the twoholes become continuous each other and the turned down portion of thedevice for transporting an appliance is contained in the guide pipe.

For making it easy to transport the appliance to be implanted it ispreferable that a pair of strings each of which has a loop at the tipthereof are provided for each of the wire rings respectively, that thestrings are engaged with the tubular cover at the positions of thecircumference of each wire rings which correspond to the midpointsbetween two adjacent dividing points of the front end wire ring, and oneof the strings is wound around the wire ring clockwise until it reachesthe backward of the wire ring while the other string is wound around thewire ring counterclockwise until it reaches the backward of the wirering, that a retaining rod is passed through the part at which each ofthe loops overlaps, and that each of the strings is tied each other soas to keep each of the wire rings in a collapsed condition.

For making use of the appliance to be implanted more generally eventhough the shape of the portion into which the appliance to be implantedis implanted varies it is effective to adopt a method of using theappliance to be implanted that at least two appliances to be implantedare prepared, that the front end wire ring of the appliance to beimplanted which is inserted later locates in front of the rear end wirering of the other appliances to be implanted which is inserted former,and that the appliance is connected to the adjacent appliance with eachother partially overlapped at the adjacent position. In this case, it isespecially preferable that the appliance to be implanted arrangeddownstream has a diameter which is smaller than that of the appliance tobe implanted arranged upstream and the appliance to be implanteddownstream is partially inserted into the appliance to be implantedupstream.

With the appliance to be implanted and the method of collapsing theappliance to be implanted in accordance with the invention, theoperation of collapsing the appliance to be implanted can be conductedsmoothly and the condition of which the appliance is implanted becomessatisfactory. In other wards, as the intermediate wire ring is collapsedinto a wavy shape having the same phase as that of the front end wirering, to put it in an extreme way each of the points on thecircumference corresponding to the dividing points forms a peak of amountain or a bottom of a valley formed between two mountains by takingturns while the positions corresponding to midpoints between eachadjacent two of the dividing points move neither frontward nor rearwardat all. As the intermediate wire rings are fixedly attached to thetubular cover at several points each spaced apart, the portions of theintermediate wire ring which bent most when being folded are free of thetubular cover. This makes the intermediate wire ring free from draggingresistance from the tubular cover, thereby to secure the free movementto be collapsed with ease. In addition, as the intermediate wire ring iscollapsed into a wavy shape as well as the front end wire ring, thewhole appliance is given a big folding rate, thereby to secure a compactcollapsed state and good transporting movement through a catheter for arelatively bulky appliance to be implanted. In addition, in accordancewith the arrangement, if the appliance to be implanted is released at atarget position in a blood vessel, the dividing points are restoredtoward right-angled direction to the blood vessel, and the end portionof the appliance to be implanted certainly open and does not close theinner space thereof. This helps the appliance to be implanted toappropriately follow the movement of the constantly pulsating bloodvessel with close adherence as well as improves a rate of successfulimplantation. The above-mentioned operation functions for not only asimple tubular shaped appliance to be implanted but also a bifurcatedY-shaped appliance to be implanted.

Elastic protective material circumferentially covering the wire rings ofthe appliance to be implanted is useful to prevent the inner wall of ahuman organ from being damaged by direct contact with the wire rings.The protective material also acts as a seal to attach both ends of theappliance to be implanted tightly to the inner wall of a human body,thereby to effectively prevent leakage of blood through the ends of theappliance when implanted.

When thorns are provided projecting from the wire rings, they stick intothe inner wall of a human organ to be embedded therein so that the wholeappliance is fixed to the human organ. Therefore, the thorns effectivelyprevent the appliance to be implanted from being displaced or evencarried by blood flow downstream in a blood vessel.

It can effectively improve the tubular shape of the whole appliance tobe implanted in the strength and the construction if at least two of theadjacent wire rings are connected by a rod.

If the number of the dividing points is four, it is extremely easy tofold the appliance to be implanted by using a pair of forceps. Namely,if the appliance to be implanted is inserted into the funneled tube withthe whole appliance picked by forceps along a generatrix which passestwo points facing each other on the front end wire ring each of which isprovided with a hooking means, the points picked by the forceps arecarried in advance from the big portion to the small portion of thefunneled tube while other points approach each other with restrained bya tapered surface of the inner wall of the funneled tube from movingforward following the points having a hooking means. The points pickedby the forceps inevitably form a peak of a mountain and the midpointsbetween two adjacent points picked by the forceps form a bottom of avalley, thereby to fold the appliance to be implanted into anappropriate wavy shape. In this case, the intermediate wire rings areeasily transformed to the direction so as to form a mountain and avalley with the points on the circumference of the intermediate wirering corresponding-to the midpoints between two adjacent dividing pointson the front end wire ring serving as fulcrum, which makes the operationof folding the appliance smooth and appropriate.

In this case, if the forceps are provided with serrate engaging member,the pushing force applied to the forceps can effectively be transformedto a force of propelling the appliance to be implanted by making use ofthe serrations of the engaging member when inserting the appliance to beimplanted, and the forceps can be smoothly withdrawn from the funneledtube without dragging the appliance to be implanted by making use of theserrations of the engaging member.

If the points on the circumference of the intermediate wire ringcorresponding to the midpoints between two adjacent dividing points aretied by a pair of strings each of which has a loop at the tip thereofand a retaining rod is passed through the part at which each of theloops overlaps, the appliance to be implanted is kept in a collapsedcondition. This makes it possible that the appliance to be implanted isinserted into a catheter without using a funneled tube. This also makesit easy to adjust the position at which the appliance is implantedbecause the appliance to be implanted can be kept in a collapsedcondition after it is released from the catheter. This method is usefulespecially for the appliance to be implanted whose shape is bifurcated.In addition, if the retaining rod is pulled out, the loops overlappingeach other are released from binding and free to move. As the portion atwhich the stings are sewed to the tubular cover is loosened, the forceto keep the appliance to be implanted in a collapsed condition isreleased, and then the appliance to be implanted is restored to theoriginal shape without bound by strings. In this case, as the stringsare used as not a single but a pair, even though one of the stringsmight get stuck on the way, the appliance to be implanted is guaranteedto restore by another string.

If the retaining rod comprising a tube and a wire is used and the tubeis pulled out with the wire left in a collapsed condition, the wholeappliance to be implanted remains flexible with the wire functioning asthe retaining rod. This makes it possible that the appliance to beimplanted passes smoothly through the bent portion or the like whentransported in a collapsed condition.

If the appliance to be implanted has previously been contained in a pipemember having a diameter bigger than that of the small portion of thefunneled tube and smaller than that of the big portion of the funneledtube, it saves the operation of collapsing the appliance to beimplanted. Just inserting the pipe member into the funneled tube so asto make abutting engagement with the inner surface of the funneled tubeand pulling out the appliance to be implanted from the side of the frontend wire ring enables the appliance to be implanted to be collapsed intoa smaller size so as to be inserted into the small portion of thefunneled tube and a catheter.

With the method of using the appliance to be implanted in accordancewith the invention, a Y-shaped appliance to be implanted can effectivelybe transported to be implanted into a portion at which a blood vesselbranches out into two, thereby to greatly improve the appliance to beimplanted in use generally and practically.

In this case, if a catcher is inserted into near the portion to beimplanted and catches a device for transporting the appliance which isattached to one of the rear end wire rings of the appliance to beimplanted, it can be extremely easy to fix the appliance to be implantedinto a bifurcated portion to be implanted.

If the front end of the device for transporting the appliance is engagedwith the appliance to be implanted and the base end of the device fortransporting the appliance is turned down so as to be caught by thecatcher, it becomes easy to arrange the device for transporting theappliance at a position where it is easy for the catcher to catch. As aresult of this, the accuracy and the efficiency of implanting theappliance to be implanted is effectively improved.

During the above process if a guide pipe having a valve is used, itbecomes possible to guide the base end of the device for transportingthe appliance to a position preferable to be caught with not onlypreventing bleeding but also preventing the device for transporting theappliance from entangling in the appliance to be implanted.

If a pair of the appliances to be implanted in accordance with theinvention are connected to partially overlap, it can change the lengthof the connected appliances relatively freely by adjusting the length ofthe overlapped portion. This makes it possible to commonly use the samestandardized appliances to be implanted for the organ into which theappliance is to be implanted even though the length or the shape of theorgan varies a little. If the appliance to be implanted arrangeddownstream is partially inserted into the appliance to be implantedarranged upstream, not only both of the appliances to be implanted canbe connected smoothly but also the appliance can be implantedsatisfactory so as to fit the shape of the blood vessel into which theappliance is to be implanted because usually blood vessels are graduallysmaller in diameter from upstream to downstream.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an artificial blood vessel used in oneembodiment of the invention.

FIG. 2 is a vertical cross-sectional view of part of the artificialblood vessel.

FIG. 3 is an enlarged perspective view of part of the intermediate wirering constituting the artificial blood vessel.

FIG. 4 shows a condition how the intermediate wire ring is fixed to thetubular cover.

FIG. 5 is a perspective view of a device for transporting the artificialblood vessel, used in the embodiment.

FIG. 6 is a perspective view of a device for introducing the artificialblood vessel, used in the embodiment.

FIG. 7 is a perspective view of a cartridge constituting the device forintroducing the artificial blood vessel.

FIG. 8 is an enlarged vertical cross-sectional view of part of theattachment shown in FIG. 6.

FIG. 9 is an enlarged vertical cross-sectional view of part of thecartridge shown in FIG. 6.

FIG. 10 is a side view showing a funneled tube, used in the embodiment.

FIG. 11 is a side view showing forceps, used in the embodiment.

FIG. 12 is a perspective view of the artificial blood vessel throughwhich the device for transporting the artificial blood vessel is looselyinserted.

FIG. 13 is a perspective view showing a step to hold the artificialblood vessel by means of the device for transporting the artificialblood vessel.

FIG. 14 is a perspective view showing a step to hold the artificialblood vessel by means of the device for transporting the artificialblood vessel.

FIG. 15 is an enlarged perspective view showing part of the artificialblood vessel kept by the device for transporting the artificial bloodvessel.

FIG. 16 is a perspective view showing a step to introduce the artificialblood vessel into a catheter.

FIG. 17 is a perspective view showing a step to introduce the artificialblood vessel into the catheter.

FIG. 18 is a perspective view showing a step to introduce the artificialblood vessel into the catheter by means of the forceps.

FIG. 19 shows the front end wire ring of the artificial blood vesselbeing folded.

FIG. 20 shows the front end wire ring of the artificial blood vesselbeing folded.

FIG. 21 shows the front end wire ring of the artificial blood vesselbeing folded.

FIG. 22 shows the front end wire ring of the artificial blood vesselbeing folded in a funneled tube.

FIG. 23 is a perspective view showing the intermediate wire rings of theartificial blood vessel being folded.

FIG. 24 is an expanded view showing the intermediate wire rings of theartificial blood vessel being folded.

FIG. 25 is a partly cut-out side view showing the artificial bloodvessel inserted into the cartridge.

FIG. 26 is a diagram showing each of the wire rings being folded.

FIG. 27 is a partly cut-out side view showing the cartridge from whichthe funneled tube is drawn out.

FIG. 28 is a partly cut-out side view showing the cartridge connected tothe attachment.

FIG. 29 is a cross-sectional view showing the artificial blood vesseltransported to the affected portion.

FIG. 30 shows a step to release the artificial blood vessel at anaffected part in a blood vessel.

FIG. 31 shows a step to release the artificial blood vessel at theaffected part in the blood vessel.

FIG. 32 is a cross-sectional view showing the artificial blood vesselreleased at the affected portion in the blood vessel.

FIG. 33 shows a step to expand the artificial blood vessel by means of aballoon catheter.

FIG. 34 is a perspective view of the artificial blood vessel use inanother embodiment of the invention.

FIG. 35 is a perspective view showing the artificial blood vessel whichhas previously been folded by means of a string.

FIG. 36 is a perspective view showing a procedure of folding theartificial blood vessel by means of a string.

FIG. 37 is a perspective view showing the artificial blood vessel aroundwhich a string is wound.

FIG. 38 is a perspective view showing a device for transporting theartificial blood vessel.

FIG. 39 is a perspective view showing a device for transporting theartificial blood vessel to pull the rear end wire ring of the artificialblood vessel shown in FIG. 38.

FIG. 40 shows the principle how the artificial blood vessel of theembodiment is used.

FIG. 41 shows the principle how the artificial blood vessel of theembodiment is used.

FIG. 42 shows the principle how the artificial blood vessel of theembodiment is used.

FIG. 43 shows the principle how the artificial blood vessel of theembodiment is used.

FIG. 44 is a diagram showing an artificial blood vessel in accordancewith a different embodiment of the invention.

FIG. 45 is a diagram showing an artificial blood vessel in accordancewith a further different embodiment of the invention.

FIG. 46 is a perspective view showing a device for transporting theartificial blood vessel in accordance with a further differentembodiment of the invention.

FIG. 47 shows a method of collapsing the artificial blood vessel inaccordance with further different embodiment of the invention.

FIG. 48 shows a method of using the artificial blood vessel inaccordance with further different embodiment of the invention.

FIG. 49 is a view showing a condition of a method of using in accordancewith further different embodiment of the invention.

FIG. 50 is a view showing a condition just before the method of usinghas been finished.

FIG. 51 is a view showing a valve used for a sheath of the embodiment.

FIG. 52 is a view showing other valve which can be utilized instead ofthe valve shown in FIG. 51.

FIG. 53 is a view showing a valve used for a guide pipe of theembodiment.

FIG. 54 is a view showing a modification of the device for transportingan artificial blood vessel.

FIG. 55 is a cross-sectional view taken along the line X1--X1 of FIG.54.

FIG. 56 is a cross-sectional view taken along the line Y1--Y1 of FIG.54.

FIG. 57 is a cross-sectional view taken along the line Z1--Z1 of FIG.54.

FIG. 58 is a view of the device for transporting the artificial bloodvessel shown in FIG. 55 viewed from a different angle.

FIG. 59 is a view showing a modification of the device for transportingthe artificial blood vessel.

FIG. 60 is a cross-sectional view taken along the line X2--X2 of FIG.59.

FIG. 61 is a cross-sectional view taken along the line Y2--Y2 of FIG.59.

FIG. 62 is a cross-sectional view taken along the line Z2--Z2 of FIG.59.

FIG. 63 is a view of the device for transporting an artificial bloodvessel shown in FIG. 59 viewed from a different angle.

FIG. 64 is a cross-sectional view showing a modification correspondingto FIG. 62.

FIG. 65 is a view showing a modification different from the above of thedevice for transporting the artificial blood vessel.

FIG. 66 is a cross-sectional view taken along the line X3--X3 of FIG.65.

FIG. 67 is a cross-sectional view taken along the line Z3--Z3 of FIG.65.

FIG. 68 is a view showing a modification different from the above of thedevice for transporting the artificial blood vessel.

FIG. 69 is a cross-sectional view taken along the line Z4--Z4 of FIG.68.

FIG. 70 is a cross-sectional view taken along the line Z3--Z3 of FIG.68.

FIG. 71 is a view showing a modification of an artificial blood vessel.

BEST MODES OF EMBODYING THE INVENTION

The invention will be described in detail with reference to theembodiments thereof shown in the accompanying drawings.

The artificial blood vessel A as the appliance to be implanted, which iscollapsed by the method in accordance with this invention, comprises, asshown in FIG. 1, a cover 7, end wire rings 101, 102 and intermediatewire rings 12.

The cover 7, as shown in FIG. 2, consists of a flexible, tensile sheetshaped into a tube of bellows, the normal diameter of which generallycorresponds to the shape of that portion of the human blood vessel atwhich the artificial blood vessel A is to be implanted. The sheet of thecover 7 is, for example, of warps extending in the axial direction ofthe artificial blood vessel A woven with wefts extending in thecircumferential direction thereof, wherein the warps are ofmono-filament made of polyester (about 15 denier) and the wefts are ofmulti-filament made of a plurality of superfine filaments (about 50denier) interwoven. The wefts are additionally woven with thread ofpolyethylene of about 10 denier to make the sheet of the cover 7 thinnerand stronger. The cover 7 is coated, if necessary, with waterproofmaterial, for example, collagen or albumin, to prevent leakage of blood.

The front and rear end wire rings 101, 102, whose inner diametergenerally corresponds to that of the above-mentioned cover 7, areaxially spaced apart and arranged face to face, and are fixed to theopposite ends of the cover 7 by suturing or with adhesive as shown inFIG. 2. As shown in FIG. 1, loop-shaped front hooking means 13 areformed at a pair of dividing points 411 and 431 facing each other acrossthe axis of four dividing points 411, 421, 431, 441 each of whichequally quadrisects the circumference of the front end wire ring 101.The hooking means 13 in accordance with the embodiment are formed ofstring. It may not necessarily be of string, but a hole directly formedon the cover 7 may be utilized as the hooking means, if there is notrouble. The circumferences of the front and rear end wire rings 101,102 are covered with protective braid members 10a, as shown in FIGS. 1and 2, which are closely fixed to the end wire rings 101, 102 atappropriate positions with thread, adhesive or the like. The protectivebraid members 10a are made of, for example, polyester fiber tied up in abundle like cotton. For especially small in diameter blood vessels intowhich the artificial blood vessel A is to be implanted the protectivebraid members 10a are preferably attached to the positions displacedahead to the end wire rings 101, 102. This is because the protectivebraid members 10a can be pushed to move to appropriate positions atwhich adjacent the end wire rings 101, 102 is covered as shown imaginarylines in FIG. 2 when transporting resistance is applied to.

A plurality of intermediate wire rings 12, each of which comprises, asshown in FIGS. 1 through 4, wire rings 12a wrapped with protective film12b made of cloth or the like, are arranged axially andgeneral-equidistantly spaced between the front and rear end wire rings101 and 102, and fixed to the cover 7 at specified positions on thecircumference thereof with thread, adhesive or the like. The specifiedpositions are the points 513, 523, 533, and 543 on the circumferenceeach of which corresponds to the midpoint 511 between the dividingpoints 411, 421 of the end wire ring 101, the midpoint 521 between thedividing points 421, 431, the midpoint 531 between the dividing points431, 441 and the midpoint 541 between the dividing points 441, 451respectively, more specifically, the points at which each of thegeneratrices ι1, ι2, ι3, and ι4 passing through the midpoints 511, 521,531, and 541 of the end wire rings 101 crosses the intermediate wirerings 12. The above-mentioned front and rear end wire rings 101, 102 andthe intermediate wire rings 12 help keep the tubular shape of the cover7.

Some of the intermediate wire rings 12 are provided with thorns 12a1which are formed at two diametrically opposite positions on each of thecircumference thereof and which stick into a human organ so as to beembedded therein. In particular, the wires 12a of the intermediate rings12 as well as those of the front and rear end wire rings 101, 102 aremade of Ti--Ni alloy or the like. The wires of Ti--Ni alloy have a highresilient-restoring force, but are hard to weld. Then as shown in FIG.3, a partially cylindrical shaped fixing member 12c into which theintermediate wire ring 12 is loosely inserted and a thorn 12a1 preformedinto U-shape or V-shape are prepared. Then the thorn 12a1 is passedthrough and inserted into the gap between the intermediate wire ring 12and the fixing member 12c. And finally the fixing member 12c is rivetedand bound with a string or the like so as to fix the thorn 12a1 to theintermediate wire ring 12. The positions at which each of the thorns12a1 is provided correspond to the above-mentioned positions 513, 523,533 and 543.

In order to implant the artificial blood vessel A of the above-mentionedconstruction into a target organ of a human body, a device B fortransporting the artificial blood vessel (see FIG. 5) is used totransport the artificial blood vessel A to the target organ of the humanbody through the catheter 8 and a device C for introducing theartificial blood vessel (see FIG. 6) is used to introduce the artificialblood vessel A into the catheter 8.

The device B for transporting the artificial blood vessel, as shown inFIG. 5, comprises a flexible metallic tube 2 whose front end portion isconnected to a helical spring 2a for guiding, a side window 1 formedadjacent the front end of the tube 2, a pair of strings 4 having boththeir ends fixed to the tube 2 adjacent the side window 1 and theirmiddle portions formed into loops to be looped portions 4a, and a lengthof wire 3 slidably inserted into the tube 2. Instead of theabove-mentioned helical spring 2a for guiding, a flexible tube may beused. The device for transporting the artificial blood vessel maycomprise only the tube 2 and a length of wire 3, which will be describedlater.

The device C for introducing the artificial blood vessel, as shown inFIG. 6, comprises an attachment 5 integrally connected to the catheter 8through an open end 8a thereof, and a cartridge 6 removably attached tothe attachment 5. As shown in FIGS. 6 and 8, the attachment 5 comprisesa first and a second annular member 51, 52 which are internally threadedto form female screws, and a third annular member 53 which is externallythreaded to form male screws at opposite ends, which engages theabove-mentioned female screws thereby to connect the internal space ofthe first and the second annular members 51, 52 at its male screw part.The catheter 8 is formed to have an open end 8a of a little largerdiameter and attached to the tip of the male screw of theabove-mentioned third annular member 53 at its open end 8a. Then thethird annular member 53 is liquidtightly joins the interior of the openend 8a of the catheter 8. Inside the second annular member 52 providedis a check valve 55 made of elastic membrane to close the open endthereof and outside of it fittingly provided is a cylinder-shapedhelical member 52a having a helical groove. The cartridge 6, as shown inFIGS. 6, 7 and 9, comprises first and second annular members 61, 62which are internally threaded to provide internal female screws, a thirdannular member 63 which is externally threaded to form male screws atopposite ends, which engage the above-mentioned female screws atopposite ends to connect the first and second annular members 61, 62, astraw member 64 whose rear end is liquidtightly attached to the tip ofone of the male screw parts of the third annular member 63 and the frontend of which is extending toward the direction to which the cartridge 6is inserted, a cylinder-shaped guide pipe 65 having an internal diameterwhich can contain the straw member 64, one of whose ends integrallyconnected to the first annular member 61 and the other end thereofprovided with a big portion 65a, and a cap 66 which is slidably movablealong the axial direction of the guide pipe 65 and loosely fit to theexternal of the guide pipe 65 and inside of which formed is a helicalgroove which helically connects the helical member 52a of the attachment5. A check valve 68 made of elastic membrane is provided inside thesecond annular member 62 to close the open end thereof.

As shown in FIG. 6, the straw member 64 of the cartridge 6 is soconstructed that the front end portion 6a thereof is removably fittedinto the rear end portion 5a of the attachment 5. In particular, asshown in FIGS. 6, 8, and 9, the bore diameter d1 adjacent the open end8a of the catheter 8 is set generally the same as or a little largerthan the bore diameter d2 of the straw member 64 of the cartridge 6, andthe length L2 of the straw member 64 extending from the big portion 65aof the guide pipe 65 is set approximately equal to the length L1 betweenthe end portion 5a of the attachment 5 and the position a little deepfrom the open end 8a of the catheter 8. The big portion 65a formed onone end of the cartridge 6 is made abutting engagement with the endportion 5a of the attachment 5 with the cap 66 helically mounted to theouter surface of the cylinder-shaped helical member 52a as shown in FIG.28, and the front end portion 6a of the straw member 64 is inserted intothe open end 8a of the catheter 8 so that the straw member 64 issmoothly connected to inside of the open end 8a of the catheter 8. Theabove-mentioned check valves 55, 68 are made of elastic membrane, ineach of which a normally closed hole, not shown in drawings, is formed.

A funneled tube 18 as a guide tube and forceps 19, as shown in FIGS. 10and 11, are provided to help collapse the artificial blood vessel A. Thefunneled tube 18 is provided with an enlarged inlet opening 18a of anenlarged diameter at the rear end portion, through which the tubularartificial blood vessel A is inserted into the funneled tube 18. Thefunneled tube 18 is gradually reduced in diameter from the enlargedinlet opening 18a to end in a tubular connector 18b of a smallerdiameter at the front end portion thereof, so that the tube 18 has atapered inner surface 18d. The funneled tube 18 is, as shown in FIG. 25,removably connected to the cartridge 6 by inserting the front connector18b into the rear end portion 6b of the cartridge 6. The forceps 19 areused for picking the artificial blood vessel A so as to insert it intothe funneled tube 18. The forceps 19 are provided on its picking surfacewith an engaging member 19a having serrations against the direction tobe inserted and for the direction to be pulled out so as to lessen thesliding resistance between the forceps 19 and the artificial bloodvessel A when the forceps 19 are inserted relatively smaller than thatwhen pulled out.

The process of collapsing the artificial blood vessel A and implantingit into a position to be implanted, namely, a target portion (anaffected part 26 in FIG. 29) of a blood vessel 9 by means of the deviceB for transporting the artificial blood vessel and the device C forintroducing the artificial blood vessel of the above-mentionedconstructions, will now be described below.

First, the tube 2 of the device B for transporting the artificial bloodvessel is inserted through the artificial blood vessel A as shown inFIG. 12, and each of a pair of strings 4 is passed through each hookingmeans 13 of the artificial blood vessel A as shown in FIG. 13, and thelooped portions of the strings 4 overlap as shown at 4a. Next, a wire 3has its forward end taken out of the side window 1 as shown in FIG. 14,and the overlapped portions of the looped portions 4a are hooked overthe wire 3, and then the wire 3 has its forward end inserted again intothe tube 2 through the side window 1 so as to hold the artificial bloodvessel A on the wire 3 and the tube 2 through the strings 4 as shown inFIG. 15. Then; the artificial blood vessel A is inserted into thecartridge 6 shown in FIG. 6 through the funneled tube 18 and with theforceps 19. In particular, the forceps 19 are put along the generatriceseach of which passes through the dividing points 411 and 431 with acommon front pull string 20 being passed through the front hooking means13 provided at the dividing points 411, 431 on the front end wire ring101 of the artificial blood vessel A as shown in FIG. 16. Prior to thisoperation a balloon catheter 23, as shown in FIG. 17, may be attached tothe tube 2, if necessary. The balloon catheter 23 comprises a pipe 23a,a balloon 23b formed on the front end portion of the pipe 23a, and anopening 23c provided in the rear end of the pipe 23a for air to beintroduced into or taken out of the abovementioned balloon 23b throughthe pipe 23a. The pipe 23a is loosely fitted over the tube 2 of theabove-mentioned device B for transporting the artificial blood vessel.In other words, the rear end portion of the tube 2 of the device B fortransporting the artificial blood vessel is drawn outside from the rearend of the balloon 23b of the balloon catheter 23 while the front endportion of the tube 2 is passed through the balloon 23b of the ballooncatheter 23 and exposed outside, with the portions of the catheter 23through which the tube 2 is passed being airtightly sealed. The rear endportion of the pipe 23a is removably connected to the tube 2 of thedevice B for transporting the artificial blood vessel by a fixing member24, and the balloon catheter 23 and the tube 2 of the device B fortransporting the artificial blood vessel can be moved together as a unitlongitudinally when the fixing member 24 is fastened, and the ballooncatheter 23 can be moved longitudinally relative to the tube 2 of thedevice B when the fixing member 24 is loosened. The balloon catheter 23is so positioned that the front end thereof is spaced about 2 to 3 cmapart from the rear end of the artificial blood vessel A loosely fittedover the tube 2. Then the fixing member 24 on the balloon catheter 23 isfastened to fix the catheter 23 to the tube 2 so that the catheter 23and the tube 2 can be moved together as a unit.

Before or after the above step, the funneled tube 18 is attached to acartridge 6 as shown in FIG. 18. In attaching the funneled tube 18 tothe cartridge 6, the connector 18b of the funneled tube 18 is insertedinto the annular member 62 of the cartridge 6 so that the check valve 68of elastic membrane provided inside the annular member 62 is pushed openby the connector 18b of the funneled tube 18 as shown in FIG. 25, andthe connector 18b is inserted a little deep into the straw 64 of thecartridge 6. Then the artificial blood vessel A is inserted into insideof the funneled tube 18 through the enlarged inlet opening 18a withpicked by forceps as shown in FIG. 18. The front pull string 20 isinserted into the funneled tube 18 through the enlarged inlet opening18a thereof and withdrawn forward through the straw 64 at the front endof the cartridge 6, with the tube 2 inserted a certain length into thefunneled tube 18. Under the condition, the front pull string 20 ispulled forward to introduce the artificial blood vessel A into thefunneled tube 18 through the enlarged inlet opening 18a thereof.

Then the front end wire ring 101 of the artificial blood vessel A isdeformed to be flat as shown in FIGS. 19 and 20 with the positionspicked up by the forceps 19, namely the dividing points 411, 431approaching toward each other to be pushed into the funneled tube 18while the other dividing points 421, 441 restrained from the movementtoward the tubular connector 18b by sliding contact with the taperedinner surface 18d of the funneled tube 18. When the front end wire ring101 reaches adjacent the tubular connector 18b of the funneled tube 18,the front end wire ring 101 as a whole is folded into a regular wavyshape with the dividing points 411, 431 forming forwardly directed peaksand other dividing points 421, 441 forming the bottoms of forwardlydirected valleys. The intermediate wire rings 12 and the rear end wirering 102 also begin to transform into a wavy shape having the same phaseas that of the front end wire ring 101, as shown in FIG. 22, becauseboth of them follow the movement of the front end wire ring 101 towardthe tubular connector 18b with picked by forceps 19. If focused on theintermediate wire ring 12, as the intermediate wire ring 12 is, as shownin FIGS. 23 and 24, fixedly attached to the tubular cover 7 only at thepoints 513, 523, 53, 543 of the circumference thereof each of whichcorresponds to the midpoints between two adjacent dividing points, thepoints picked by the forceps 19 protrude forward and other points isleft behind with the above-mentioned points 513, 523, 533, 543 servingas fulcrum, thereby to cause the intermediate wire ring 12 twisted andtransformed into a wavy shape without dragging the tubular cover 7.

Under this condition, the forceps 19 are withdrawn from the funneledtube 18 and the front pull string 20 is pulled forward to fartherintroduce the artificial blood vessel A into the cartridge 6. As thefront pull string 20 is pulled forward, the pulling force applied to thefront end wire ring 101 is transmitted through the tubular cover 7 tothe intermediate wire rings 12 and the rear end wire ring 102, therebyto cause the intermediate wire rings 12 and the rear end wire ring 102to follow the movement of the front end wire ring 101. With theartificial blood vessel A perfectly contained in a cartridge 6 as shownin FIG. 25, the intermediate wire rings 12 and the rear end wire ring102 are collapsed into a small size to take a wavy shape having the samephase as that of the front end wire ring 101 as shown in FIG. 26.

As the forceps 19 are provided with the above-mentioned serrate engagingmember 19a, they can pick up and push the artificial blood vessel A intothe funneled tube 18 for certain while they can be withdrawn from thefunneled tube 18 with leaving the artificial blood vessel A in thefunneled tube 18 by slipping smoothly between the artificial bloodvessel A and the funneled tube 18. As the rings 101 and 102 are folded,it is needless to say that the braid members 10a circumferentiallyarranged about the front and rear end wire rings 101, 102 are alsofolded to take a wavy shape with following the front and rear end wirerings 101, 102.

Under the condition, the front pull string 20 is untied or cut at anappropriate position thereof and pulled at its end so as to be withdrawnfrom the front hooking means 13, and the funneled tube 18 is withdrawnfrom the cartridge 6. Consequently, the artificial blood vessel A iscontained in the straw 64 of the cartridge 6, as shown in FIG. 27, andonly the balloon catheter 23 in which the tube 2 is provided is exposedoutside through the rear end portion 6b of the cartridge 6 with thecheck valve 68 opened a little.

On the other hand, the catheter 8 has been previously inserted throughas shown in FIG. 28, for example, the coxal artery adjacent the groin Finto the blood vessel 9 as far as the front end of the catheter 8 hasbeen positioned a little beyond the affected portion 26 such as ananeurysm of the aorta as shown in FIG. 29. The attachment 5 connected tothe open end 8a of the catheter 8 is, as shown in FIG. 28, exposedoutside the body. Next, the straw 64 of the cartridge 6 into which theartificial blood vessel A has been inserted is pushed into theattachment 5 through the rear end portion 5a thereof until the bigportion 65a makes abutting engagement with the rear end portion 5a withthe check valve 5 opened as shown in FIG. 28 and the cap 66 is advancedto helically connect to the outer surface of the helical member 52a.Then the straw 64 of the cartridge 6 is positioned so that the front end6a thereof is smoothly connected to the inner surface of the open end 8aof the catheter 8 and this condition is kept by the helical connectionof the cap 66 and the helical member 52a. Under the condition, theballoon catheter 23 is gripped and the balloon catheter 23 is pushed soas to be inserted gradually deeply into the catheter 8. As the tube 2is, as shown in FIG. 17, connected to the balloon catheter 23 throughthe fixing member 24 and the artificial blood vessel A is held by thetube 2, movement of the balloon catheter 23 causes the artificial bloodvessel A to be transported gradually to the deep position in the body.The balloon catheter 23 is pushed until the front end of the tube 2 ispositioned at the front end of the catheter 8, as shown in FIG. 29. Atthis time the artificial blood vessel A is positioned at the affectedportion 26 as the target position. Then, as the catheter 8 is withdrawnas shown in FIG. 30, with the balloon catheter 23 and the tube 2 intowhich the wire 3 is inserted left at the objective position, thecollapsed artificial blood vessel A in the catheter 8 is released at theaffected portion 26 in the blood vessel 9 while expanding gradually fromthe front end as shown in FIGS. 30, 31 and 32. The released artificialblood vessel A is restored to its original tubular shape and urgedagainst the inner wall of the blood vessel 9. In other words, when theartificial blood vessel A collapsed into small as shown in the figuresis released from the catheter 23, each of the quadrisecting pointselastically restores to a direction generally perpendicular to the bloodvessel 9. Consequently, the artificial blood vessel A restores itselfwith each end portion thereof open and the internal space of theartificial blood vessel A is not closed by the internal wall of theblood vessel 9. Then the fixing member 24 shown in FIG. 17 is loosenedto disconnect the balloon catheter 23 from the tube 2, and the ballooncatheter 23 is advanced along the tube 2 into the artificial bloodvessel A with the tube 2 kept at the objective position as far as thefront end of the balloon catheter 23 reaches the front end of theartificial blood vessel A as shown in FIG. 33, whereupon the balloon 23bis inflated by introducing air through the opening 23c as shown in FIG.33 thereby to restore the artificial blood vessel A completely to itsoriginal shape and securely fix it onto the inner wall of the bloodvessel. At this time the thorns 12a1 stick into the inner wall of theblood vessel 9 and are embedded therein. After the artificial bloodvessel A has been thus fixed, the balloon 23b of the balloon catheter 23is deflated by drawing air through the opening 23c and the ballooncatheter 23 is pulled out from the artificial blood vessel A by pullingthe pipe 23a rearwardly. Then it is confirmed that the artificial bloodvessel A has been fixed onto the inner wall of the blood vessel 9, andthen the wire 3 is pulled out of the tube 2. As the front end of thewire 3 passes the rear edge of the side window 1 of the tube 2 as shownin FIG. 13, the loop portion 4a of the string 4 that has been caught bythe wire 3 at the side window 1 is released from the wire 3. Under thecondition, when the tube 2 is pulled out, the string 4 slips out of thefront hooking means 13 of the artificial blood vessel A. The ballooncatheter 23 and the tube 2 are then connected again by the fastener 24and pulled out of the human body with only the artificial blood vessel Aleft at the desired position in the blood vessel 9.

As mentioned above, in accordance with the invention, the artificialblood vessel A is implanted into the affected portion 26, and restoredto its original shape thereby to effectively prevent occlusion of theaffected portion 26 in the blood vessel 9. With the above-mentionedartificial blood vessel A and its collapsing method, the artificialblood vessel A can be collapsed with ease and accuracy. In other wards,as the intermediate wire ring 12 is collapsed into a wavy shape havingthe same phase as that of the front end wire ring 101, to put it in anextreme way each of the points 413˜443 on the circumferencecorresponding to the dividing points 411˜441 forms a peak of a mountainor a bottom of a valley formed between two mountains by taking turnswhile the positions 513˜543 corresponding to midpoints 511˜541 betweeneach adjacent two of the dividing points move neither frontward norrearward at all. As the intermediate wire rings 12 are fixedly attachedto the tubular cover 7 at the points 513˜543, the portions of theintermediate wire ring 12 which bent most when being folded are free ofthe tubular cover 7. This makes the intermediate wire ring 12 free fromdragging resistance from the tubular cover, thereby to secure the freemovement to be collapsed with ease. In addition, as the intermediatewire ring 12 is collapsed into a wavy shape as well as the front endwire ring 101, the whole artificial blood vessel A can be folded into asmall size and even through a relatively bulky artificial blood vessel Acan be effectively transported to the affected portion 26 through acatheter 8. In addition, if the artificial blood vessel A is released ata target position in a blood vessel, the dividing points 411˜441 and theintermediate wire rings 12 are restored toward right-angled direction tothe blood vessel together with the front end wire ring 101, and theartificial blood vessel A does not close the inner space thereof. Thiscertainly improves a rate of successful implantation.

In this embodiment, as the flexible braid members 10a arecircumferentially arranged on the front and rear end wire rings 101, 102of the artificial blood vessel A, the inner wall of a human organ can beprevented from being damaged by direct contact with the front and rearend wire rings 101, 102 in addition to the advantage that both ends ofthe implanted artificial blood vessel A can be sealed tightly to theinner wall of a human body, thereby to effectively prevent leakage ofblood through the ends of the artificial blood vessel A.

In this embodiment as the thorns 12a project from the intermediate wirerings 12, they stick into the inner wall of a human organ to be embeddedtherein so that the whole artificial blood vessel A is fixed to thehuman organ. Therefore, after the artificial blood vessel A has beenimplanted in the human organ, the thorns 12a1 effectively preventdisplacement of the artificial blood vessel A, which may cause thevessel A to be carried by blood flow downstream in the blood vessel.

In this embodiment, as the number of the dividing points is set four, itis possible to make effective use of the forceps 19. In other words, asdescribed above, when whole of the artificial blood vessel A is pickedby forceps 19 along the generatrices ι5, ι6 which pass through twopoints 411, 431 of the front end wire ring 101 each of which has hookingmeans 13 and is arranged face to face and is inserted into the funneledtube 18, the points picked by forceps 19 are carried ahead from theenlarged inlet opening 18a to the tapered inner surface 18d of thefunneled tube 18 and the dividing points 421, 441 each of which is notprovided with the hooking means 13 gradually approach each other withthe movement of following the dividing points 411, 431 restrained byabutting engagement with the tapered inner surface 18d of the funneledtube 18 which prevents to follow. Consequently the artificial bloodvessel A is collapsed into a regular wavy shape with the points pickedup by forceps 19 forming forwardly directed peaks and the midpointsforming the bottoms of forwardly directed valleys. The same is true withthe intermediate wire rings 12 so that the intermediate wire rings 12easily transform into a wavy shape having peaks and valleys with thepoints 513, 523, 533, 543 on the circumference thereof corresponding tothe midpoints between two adjacent dividing points of the front end wirering 101 serving as fulcra, thereby to make the movement of beingcollapsed easy and accurate.

The serrate engaging member 19a provided on the picking surface of theforceps 19 makes it very easy to insert or withdraw the forceps 19, asthe serrate engaging member 19a facing against the direction to beinserted is useful to transform the urging force applied to the forceps19 into a propelling force to the artificial blood vessel A when theartificial blood vessel A is to be inserted, while the serrate engagingmember 19a facing for the direction to be inserted makes it possible towithdraw the forceps 19 from the funneled tube 18 with the artificialblood vessel A in the funneled tube 18 left without dragging theartificial blood vessel A.

In addition, the device C for introducing the artificial blood vesselmakes it extremely easy and smooth to introduce the artificial bloodvessel A into the catheter 8. In other words, the reason why the deviceC is composed of the attachment 5 and the cartridge 6 each of which hasa check valve 55, 68 is not only to prevent blood from flowing backwardbut also to provide a strong portion with the device C to be handledeasily. Especially in this embodiment, the cap 66 is helically attachedto the outer surface of the helical member 52a so as to joint thecartridge 6 and the attachment 5 liquidtightly. Consequently, excessivebleeding while the cartridge 6 is pulled out of the attachment 5 cancertainly be prevented as well as the front end of the straw member 64of the cartridge 6 can be kept to make a smooth connection with theinternal surface of the open end 8a of the catheter 8. In addition, asthe above-mentioned cartridge 6 can be attached to the attachment 5 withaccuracy as long as the length of the straw member 64 projecting fromthe guide pipe 65 remains the same, the cartridge 6 can easily beapplied to the artificial blood vessel A in variety of length bychanging the length of the guide pipe 65 or of the straw member 64.

This invention is not limited to the above-mentioned embodiments. Forexample, if the vessel of the affected portion where the artificialblood vessel is to be implanted is different from the above mentionedand bifurcated, it is effective to use the artificial blood vessel Dshown in FIG. 34. The artificial blood vessel D is to be implanted, forexample, into the blood vessel of the groin. The artificial blood vesselD has fundamentally the same arrangement as that of the above-mentionedembodiment. This artificial blood vessel D, however, is for fitting theshape of the blood vessel into which the artificial blood vessel D isimplanted characterized by that a single front end wire ring 1101 isarranged face to parallely arranged two rear end wire rings 1102 each ofwhose diameter is smaller than that of the front end wire rings 1101,and a bifurcated tubular cover 107 connects the front end wire rings1101 and two rear end wire rings 1102. And intermediate wire rings 1121each of whose diameter is generally the same as that of the front endwire rings 1101 are arranged at the position whose diameter is the sameas that of the front end wire ring 1101, while intermediate wire rings1122 each of whose diameter is generally the same as that the rear endwire ring 1102 are arranged at the position whose diameter is the sameas that of the rear end wire ring 1102. Each of the intermediate wirering 1121, 1122 is fixed to the cover 107 at a plurality of separatepositions on the circumference thereof as the same as in the formerembodiment.

On the other hand, the artificial blood vessel D which has beenpreviously collapsed into small is inserted into the catheter andtransported to a target organ. The method of collapsing the artificialblood vessel D will be described. A pair of strings 1001, 1002 areattached to each of the wire rings 1101, 1121, 1122, 1102 of theartificial blood vessel D at the points where each of the wire rings1101, 1121, 1122, 1102 is fixed to the tubular cover 107. Theintermediate wire ring 1121 is represented for concrete explanation.First, the string 1001 is kept folded at the center thereof hooked by aneedle for operation. In this state the string 1001 is wound around theintermediate wire ring 1121 clockwise by making use of the needle untilit reaches the backward of the intermediate wire ring 1121 as shown inFIG. 36, and then sewed up at a plurality of separate positions with theneedle. The positions at which the string 1001 is sewed up fall on thegeneratrices corresponding to the midpoints between two adjacentdividing points of the front end wire ring 1101, and in this embodimentthe string 1001 is sewed up at two positions. The string 1001 ispreferably sewed to the protective film (like the protective film 12b inFIG. 2) which covers the surface of the intermediate wire ring 1121 butmay be sewed to the tubular cover 107 as long as the artificial bloodvessel D is kept liquidtight. Likewise another string 1002 is woundaround the intermediate wire ring 1121 counterclockwise and then sewedup at positions symmetric to the string 1001. Next, insert a rod 115into the artificial blood vessel D for helping the artificial bloodvessel D be collapsed. Loop portions 100a1, 100a2 each formed at each ofthe tip of a pair of strings 1001, 1002 are overlapped, into which aretaining rod 114 is inserted and then end portions 100b1, 100b2 of thestrings 1001, 1002 are tied together. The artificial blood vessel D ishelped to be collapsed by a finger or the like, if necessary. Theintermediate wire ring 1121 is gathered so that the points correspondingto the midpoints between two adjacent dividing points approach the rod115 as a string is passed through each of the points, thereby to becollapsed into a wavy shape with the dividing points between the pointsat which the string is sewed up forming the bottoms of valley and thepeaks in turn as shown in FIG. 37. This operation is done to each of thewire rings 1101, 1121, 1122, 1102. The consequence is shown in FIG. 35.As it is clear in FIG. 35, there are two retaining rods in thisembodiment. The longer retaining rod 1141 retains the area from thefront end wire ring 1101 to one of the rear end wire ring 1102 to becollapsed, and the shorter retaining rod 1142 retains the area from theintermediate wire ring 1122 located at the divergence to the other rearend wire ring 1102 to be collapsed.

The retaining rod 114 comprises a tube 114a and a wire 114b which isinserted into the tube 114a. The tube 114a is drawn out and only thewire 114b is left after the artificial blood vessel D is kept in acollapsed condition. Although the wire 114b is smaller in diameter thanthat of the tube 114a, the wire 114b can effectively bind the strings.In addition, the wire 114b can be flexibly transformed into a bendingportion of the transporting course as softer than the tube 114a. Inother words, the tube 114a is temporarily used to make it easy to foldthe artificial blood vessel D and is drawn out together with the rod 115after the artificial blood vessel D is collapsed into a small size.

Thus folded artificial blood vessel D is transported to and implantedinto a target position, namely, a bifurcated affected portion by meansof the method in accordance with the embodiment. In this embodiment,three devices B1, B2, B3 for transporting the artificial blood vesselare used as shown in FIG. 38. The first device B1 for transporting theartificial blood vessel is the same as that used in the formerembodiment, namely, the one which is inserted into the tube 23a of theballoon catheter 23 with the front tip passed through the artificialblood vessel D and projecting to reach the most front position and keepsa front end wire ring 1101 with a string hooking a front hooking means113 of the front end wire ring 1101. The second device B2 fortransporting the artificial blood vessel is inserted into an elongatedhole formed on the thickness of the tube 23a of the balloon catheter 23with the front tip thereof drawn outside in front of the balloon 23b andkeeps a rear end wire ring 1102 with a string 104 hooking a rear hookingmeans 113a of the rear end wire ring 1102. The third devise B3 fortransporting the artificial blood vessel is arranged parallel to theballoon catheter 23 and keeps another rear end wire ring 1102 with astring 104 hooking a rear hooking means 113a of the rear end wire ring1102. The tube 102 of the device B3 for transporting the artificialblood vessel is of especially softer material than that of other devicesfor transporting the artificial blood vessel. The tube 102 of the deviceB3 for transporting the artificial blood vessel is provided with anelongated hole formed on the thickness thereof as well as the formerembodiment, into which the retaining rod 1142 is inserted and passedthrough. Each of these devices B1˜B3 for transporting the artificialblood vessel is inserted into a body through the cartridge 6 and theattachment 5 of the former embodiment. As the devices B1, B2 areattached to the balloon catheter 23, they can pass liquidtightly throughthe cartridge 6 and the attachment 5 with the check valve 68 of thecartridge 6 and the check valve 55 of the attachment 5 pushed to open alittle. However, if the device B3 is inserted into the check valves 68,55, opening is formed between the device B3 and each of the check valves68, 55, thereby causing to decline liquidtightness. Then for using thedevice B3, another hole (not shown in Figures) corresponding to thedevice B3 should be provided at the position deviating from the centerof each check valves 68, 55.

Next, the process of implanting the artificial blood vessel D will nowbe described below. First, the device B1 is pushed by making use of theballoon catheter 23 then like the former embodiment the balloon catheter23 is inserted into the catheter through the blood vessel of the groin.Next, the artificial blood vessel D is, as shown in FIG. 40, released atthe target position, in particular, the bifurcated affected portion. Theartificial blood vessel D is kept in a condition of being collapsed bythe retaining rod 1141, 1142. The artificial blood vessel D is locatedat a trunk of the blood vessel a little passing the affected portion byadjusting the position frontward of rearward with making use of thedevices B1, B2. Then the device B3 is pushed into a body through thecatheter 8. As the device B3 is made of soft material, it can be slackedoff toward a predetermined direction near the affected portion if aJ-shaped guide pipe F or the like is appropriately used as shown in FIG.41. Under the condition, a catcher E for catching the device fortransporting the artificial blood vessel is introduced near the affectedportion through the catheter from another bifurcated portion of thegroin. The catcher E comprises a tube e1, a wire e2 inserted into thetube e1, and a U-shaped hook e3 formed at the front tip of the wire e2and which is projecting from the tube e1, and is so constructed that thewire e2 projects out of the tube e1, the hook e3 opens at the positionwhere the wire e2 projects and that the hook e3 closes by the tube e1 atthe position where the wire e2 is inserted into the tube e1. The deviceB3 which has previously slacked off is caught by making use of thecatcher E and then drawn out of the body through another portion of thebifurcated groin. After all of the devices B1, B2, B3 are drawn out fromright and left portion of the groin as shown in FIG. 42, pulling forcetoward the direction shown by the arrow in the figure is applied to therear end wire rings 1102 of the artificial blood vessel D by making useof the devices B2 and B3. Then each of the rear end wire rings 1102 ofthe Y-shaped artificial blood vessel D is drawn from a trunk of theblood vessel into each of the bifurcated branches of the blood vessel.After the artificial blood vessel D is arranged along the bifurcatedblood vessels as shown in FIG. 43, the wire of the retaining rod 1141,1142 each attached to the device B1, B3 respectively for retaining theartificial blood vessel D in a collapsed condition is pulled out,thereby to release the artificial blood vessel D from being folded in asmall size. Then the artificial blood vessel D is restored as shown byimaginary lines in FIG. 43 and implanted into the internal wall of theaffected portion, namely, the bifurcated blood vessel. Finally, eachwire of the devices B1, B2, B3 is pulled out, thereby to release thefront and rear hooking means from being kept, which makes it possible todraw the devices B1, B2, B3 out of the body.

In accordance with the method of implanting the artificial blood vesselD, it is possible to implant an artificial blood vessel into an affectedportion with non-operational method even though the affected portionfalls on the bifurcated blood vessel. The artificial blood vessel D isnot always necessary to be folded into a small size beforehand by meansof strings 1001, 1002, it may sometimes be implanted through a catheter8 just being collapsed into a small size as well as the simplecylinder-shaped artificial blood vessel A as shown in FIG. 1. The rearhooking means 113a for pulling the rear end wire ring 1102 and thesecond device B2 for transporting the artificial blood vessel may beapplied to the rear end wire ring 102 of the artificial blood vessel Ashown in FIG. 1. This makes it possible to move the artificial bloodvessel A by adjusting the position of the artificial blood vessel Arearward or forward, after the artificial blood vessel A is releasedfrom the catheter 8 at the affected portion 26, thereby to implant theartificial blood vessel A with accuracy.

The artificial blood vessels may be restored in a cartridge by pullingout the retaining rod. It is effective that the artificial blood vesselspartially comprise a string of gold which can be X-rayed so as tomonitor the implanted condition of the artificial blood vessel.

The invention is not limited to the above-mentioned embodiments. Forexample, in the above embodiment, the front end wire ring has itscircumference divided into four equal arcs to set four dividing points.As shown in FIG. 44, a front end wire ring 2101 may have itscircumference divided into eight arcs to set eight dividing points 2411,2421, 2431, 2441, 2451, 2461, 2471, 2481, four of which 2411, 2431,2451, 2471 are provided with a hooking means and other four 2421, 2441,2461, 2481 are not provided with a hooking means. As shown in FIG. 45, afront end wire ring 3101 may have its circumference divided into sixarcs to set sic dividing points 3411, 3421, 3431, 3441, 3451, 3461,three of which 3411, 3431, 3451 are provided with a hooking means andother three 3421, 3441, 3461 are not provided with a hooking means.

In the above embodiment, the device for transporting the artificialblood vessel is provided with a pair of strings with loop portions. Thestrings need not always be provided in a pair. However, the stringsprovided in a pair are effective because a balanced pulling force can beapplied to the artificial blood vessel. The loop portions may be twistedas a whole. A device for transporting the artificial blood vesselcomprising only a tube and a wire and which is not provided with stringsmay be used. For example, as shown in FIG. 46, front hooking means 413formed on the front end wire ring 4101 are made a little longer, each ofloop portions of the front hooking means 413 are overlapped, and a wire403 pulled out of a side window 401 of a tube 402 is passed though andinserted into the overlapped loop portion so as to keep the artificialblood vessel. If there is no trouble to form holes directly on thetubular cover, it is also possible to keep the artificial blood vesselby means of a wire and a tube with making use of the holes as a hookingmeans.

Therefore, such a device for transporting the artificial blood vesselcan be used to a patch to close a hole formed on a heart or the like.

The intermediate wire rings 112 may be bridged by a supporting rod 500as shown in FIG. 34. The supporting rod 500 attached to the intermediatewire rings 112 improves the tubular shape of the artificial blood vesselD in the strength and the construction. The supporting rod 500 may beattached to the front or rear end wire ring 1101, 1102. If thesupporting rod 500 is fixed to the same position on the circumference ofthe front or rear end wire ring 1101, 1102 as that of the intermediatewire ring 112, it does not prevent the artificial blood vessel D frombeing folded.

In order to collapse the artificial blood vessel A into a small size byinserting it into a funneled tube 18 from a big portion 18a toward asmall portion 18b the artificial blood vessel A may be previouslycontained in a pipe member 600 having a diameter bigger than that of thesmall portion 18b of the funneled tube 18 and smaller than that of thebig portion 18a of the funneled tube 18 as shown in FIG. 47. Justinserting the pipe member 600 into the funneled tube 18 so as to makeabutting engagement with the inner surface of the funneled tube 18 andpulling out the artificial blood vessel A from the side of the front endwire ring enables the artificial blood vessel A to be collapsed into asmaller size so as to be inserted into the small portion 18b of thefunneled tube 18 and a catheter.

In addition, as shown in FIG. 48, two the artificial blood vessel A1, A2may be prepared and the front end wire ring 101 of the artificial bloodvessel A2 which is to be inserted later locates in front of the rear endwire ring 102 of the artificial blood vessel A2 which is to be insertedformer so that the artificial blood vessel A1 is connected to theartificial blood vessel A2 with each other partially overlapped at theadjacent position. Then the whole length of the connected the artificialblood vessel can be changed relatively freely by adjusting the length ofthe overlapped portion. This makes it possible that the artificial bloodvessel A1, A2 having the same standard can be tailored for the affectedportion 28 whose length or shape varies a little. It is especiallypreferable that the artificial blood vessel A2 arranged downstream has adiameter which is smaller than that of the artificial blood vessel A1arranged upstream and that the artificial blood vessel A2 arrangeddownstream is partially inserted into the artificial blood vessel A1arranged upstream. Thus arranged the artificial blood vessel A1, A2 areconnected smoothly as well as they can be implanted satisfactory so asto fit the shape of the blood vessel into which the artificial bloodvessels A1, A2 are to be implanted because usually blood vessels aregradually smaller in diameter from upstream to downstream. Of course,even if artificial blood vessels have the same diameter, it is notdifficult to partially insert one of the artificial blood vessels intoanother just by transforming one of the artificial blood vessels.

Next, when an artificial blood vessel is to be implanted into anaffected portion whose shape is bifurcated as described above, a morepreferable mode of embodying the invention will now be described indetail with reference to FIGS. 49 through 53.

The artificial blood vessel D shown in FIG. 49 is fundamentally the samein arrangement as that of FIG. 34. Unlike the artificial blood vessel Dwhich is inserted into a catheter 8 with the whole artificial bloodvessel D folded into a small size as shown in FIG. 35, in thisembodiment the artificial blood vessel D is inserted into a catheter 8with only a bifurcated portion of small diameter folded into a smallsize as shown in FIG. 49. The reason is to prevent the thorn body 12a1from unnecessarily hurt the tissues of the body to be implanted. This isdone by releasing at least a main portion of the artificial blood vesselD at a predetermined position from the first so as to avoid adjustingthe position of the main body after released. The artificial bloodvessel D is folded into a small size by means of the strings 1001, 1102and the retaining rod 114 like the embodiment explained with referenceto FIGS. 36 and 37. Then as shown in FIG. 49, the artificial bloodvessel D is transported to a bifurcated affected portion as a targetposition by means of the above-mentioned three devices B1, B2 and B3 fortransporting the artificial blood vessel (see FIG. 38). Unlike theabove-mentioned embodiment, no balloon catheter is attached to the firstdevice B1 for transporting the artificial blood vessel in thisembodiment, however, it is a matter of course that a balloon cathetermay be attached if necessary. In this case, the balloon catheter is notnecessarily inserted into a body together with the artificial bloodvessel D, but can be inserted into a body after the artificial bloodvessel D is transported to a target organ in the body.

As shown in FIG. 49, the first device B1 for transporting the artificialblood vessel holds the front end wire ring 1101 with the front endthereof passing through the artificial blood vessel D and protrudingtoward the forefront. The second device B2 for transporting theartificial blood vessel holds one of the rear end wire rings 1102 withthe front end thereof locating rear of the artificial blood vessel D.The third device B3 for transporting the artificial blood vessel holdsthe other rear end wire ring 1102 with the front end thereof locatingrear of the artificial blood vessel D. Like the embodiment shown in FIG.38, retaining rods 1141 and 1142 for keeping the artificial blood vesselD in a collapsed condition are attached, although not shown in FIG. 49,to the second and the third devices B2 and B3 for transporting theartificial blood vessel. Especially the third device B3 for transportingthe artificial blood vessel used in this embodiment is made of amaterial more flexible than that the other devices B1 and B2 are madeof. In addition, at least the length corresponding to a distance from agroin of a thigh to the affected portion of the base end B3a of thethird device B3 for transporting the artificial blood vessel is made ofa guide member b3x such as a helical spring which is not only flexiblebut also having a characteristic that a force can be so transmitted tothe whole part thereof by manipulating one part thereof that the wholedevice B3 can be freely rotated, inserted or pulled. The base end b3a isbent sideward along the length thereof, which makes it possible tochange the position of the base end b3a relatively big by manipulatingthe guide member b3x of the device B3.

These devices B1, B2 and B3 are inserted into a catheter 8 through thecartridge 6 and the attachment 5 shown in FIG. 28. As mentioned above,since the devices B1 and B2 are not attached to a balloon catheter, thedevices B1 and B2 are bundled together with the device B3 and insertedinto the cartridge 6 with the valve 68 pushed to open. As a result ofthis, when the cartridge 6 is attached to the attachment as shown inFIG. 28, bleeding is likely to occur from the portion through which thedevices B1, B2 and B3 are inserted. Then in this embodiment a sheath 700to prevent leakage is provided beforehand as shown in FIG. 49 at therear end of the cartridge 6. After the devices B1, B2 and B3 areinserted into the cartridge 6 together with the artificial blood vesselA, the sheath 700 is connected to the cartridge 6 with the valve 68pushed to open. In FIG. 60 the cartridge 6 and the attachment 5 providedbetween the sheath 700 and the catheter 8 are omitted. The sheath 700has fundamentally the same arrangement as that of the catheter 8 and isprovided with a valve 701 at the rear end thereof. At the center of thevalve 701 provided is a hole 711 which can be pushed to open against theelasticity of the valve 701 as shown in FIG. 51. The valve 701 is alsoprovided with other three holes 712 each of which locates radially andequally distant from the center of the valve 701 and the distancebetween each adjacent hole 712 is the same. Between the hole 711 andeach of the holes 712 provided is thick embankment 713 so as not to beeasily connected through both of the holes 711 and 712 each otherbecause of breakage. In this embodiment the first device B1 is insertedinto and passed through the hole 711 and each of the second and thirddevices B2 and B3 is inserted into and passed through two of the threeholes 712 respectively. Instead of the valve 701, a valve 702 as shownin FIG. 52 may be used. The valve 702 has holes 721 and 722 at thepositions corresponding to the holes 711 and 712 of FIG. 51. On thecircumference of each hole 721 and 722 provided are annular projectingportions 721a and 722a whose inside is dent to make thin. Thus arrangedvalve is effective for preventing breakage between the hole 721 and theholes 722. The device B3 is inserted into and passed through thecatheter 8 through a guide pipe H as shown in FIG. 49. The guide pipe His so arranged that the base end h1 locates out of the sheath 700 andthe front end h2 passes through the sheath 700 and a catheter 8 and thenlocates near a bifurcated affected portion. At the base end h1 of theguide pipe H provided is a valve 70 as shown in FIG. 53. The valve 70 isprovided with two holes 70a and 70b which can be pushed to open againstelasticity of the valve 70 and into which the front end of the device B3is inserted.

Next, the process of implanting the artificial blood vessel D will bedescribed below. Like the process shown in FIG. 25, first, the firstdevice B1, the second device B2 and the guide pipe H are inserted intothe cartridge 6 together with the collapsed artificial blood vessel D bypushing to open the hole of the valve 68. The third device B3 isinserted into the guide pipe H through the hole 70a of the valve 70provided at the base end h1 of the guide pipe H. Next, the sheath 700 isinserted into the cartridge 6 by pushing to open the valve 68 providedat the rear end of the cartridge 6. Since the devices B1, B2 and B3 areinserted into and passed though the holes 711 and 712 of the sheath 700beforehand as mentioned above, (the third device B3 is inserted into theguide pipe H) when the front end of the sheath 700 is inserted into thecartridge 6 through the valve 68, inside the cartridge 6 is connectedthrough inside the sheath 700 and the inner space is liquidtightlysealed from outside of the valve 701. After the artificial blood vesselD is transported to a predetermined position beyond groin of thebifurcated affected portion by manipulating the first device B1, theartificial blood vessel D is released from the catheter 8 as shown inFIG. 49. Accompanying to the artificial blood vessel D, the second andthird devices B2 and B3 are dragged and introduced into the body. Thethird device B3 is introduced into the body accompanying to the guidepipe H. The artificial blood vessel D is released after the main portionof the artificial blood vessel D is arranged at the predeterminedposition. The bifurcated portion of the artificial blood vessel D iskept in a collapsed condition by the retaining rod 1141 and 1142 shownin FIG. 38 after released. In this step, another bifurcated rear endwire ring 1102 is pushed to the bifurcated portion as shown by the arrowZ in FIG. 49 by means of the third device B3. Next, in this embodimentthe base end b3a of the third device B3 is turned down and inserted intothe guide pipe H. More specifically, the base end b3a of the thirddevice B3 is pushed to open the hole 70b of the valve 70 shown in FIG.53 so as to be inserted into the guide pipe H. After this, the guidemember b3x is gripped so as to push and transport the third device B3until the base end b3a is introduced into the body through the front endh2 of the guide pipe H. Under the condition, a catcher G for catchingthe device for transporting the artificial blood vessel is introducedinto near the affected portion through the catheter K from anotherbifurcated portion of the groin. The catcher G is made of a tube g1 intowhich two wire members g2 and g3 are inserted and passed through withboth of the front ends of the wire members g2 and g3 connected to form aloop. Concretely the catcher G is so arranged that a single wire memberis inserted into and passed though the tube g1 and then the front end ofthe single wire member is turned down and again inserted into the tubeg1 through the same end of the tube g1 from which the single wire memberis out. Then when the wire members g2 and g3 are pushed against the tubeg1, the loop projecting out of the tube g1 becomes bigger and when thewire members g2 and g3 are pulled from the tube g1, the loop projectingout of the tube g1 becomes smaller. Next, the base end b3a is caught bythe catcher G by manipulating the guide member b3x of the third deviceB3 and the catcher G. As mentioned above, the third device B3 is curvedaround the base end b3a so as to make it easy for the catcher G to catchthe device B3. As a result of this, it becomes easy to rotate, insert orpull the third device B3 by handling the guide member b3x which is outof the guide pipe H. After being caught by the catcher G, the base endb3a is pulled out of the body through another groin of the thigh. As thebase end b3a is pulled further, the length of the third device B3 beingout of the valve 70 of the guide pipe H becomes shorter and shorter andfinally the third device B3 strains itself between the hole 70a and thehole 70b of the valve 70. Then the valve 70 between the hole 70a and thehole 70b is artificially broken so that the third device B3 is fullycontained in the guide pipe H. The valve 70 may be broken by a surgicalknife, or a stick shaped material. If the stick shaped material is leftin the guide pipe H after the valve 70 is broken, it can effectivelyprevent bleeding from the broken part of the valve 70. Next the base endb3a of the third device B3 is further pulled out of the body throughanother groin of the thigh until only the front end of the third deviceB3 is left in the body as shown in FIG. 50. After the third device B3 ispulled out of the body, the rear end wire ring 1102 of the Y-shapedartificial blood vessel D is introduced into an appropriate position ofanother branch from the trunk of the blood vessel by being pulled towardthe direction shown by the arrow of FIG. 50. After the artificial bloodvessel D is arranged in the appropriate position, the wires of theretaining rods 1141 and 1142 (shown in FIG. 42) each of which isattached to the second and the third devices B2 and B3 respectively arepulled so as to release the artificial blood vessel D from a collapsedcondition. Then the bifurcated portions of the artificial blood vessel Dare restored to the original shape and implanted into the bifurcatedinternal wall of the blood vessel in the affected portion. Finally, eachwire 3 of the devices B1, B2 and B3 (see FIG. 15) is drawn so as to bereleased from the front end wire ring 1101 and the rear end wire ring1102. Then the devices B1, B2 and B3 can be taken out of the body.

In accordance with the above-mentioned method, the third device B3 canbe caught by the catcher G with accuracy without entangling in theartificial blood vessel D. More specifically, since the third device B3is inserted into the catheter 8 through the guide pipe H in thisembodiment, the third device B3 can be isolated from the artificialblood vessel D or the like while being transported in the catheter 8,thereby to avoid without fail inconvenience of the third device B3entangling in the artificial blood vessel D or the devices B1 and B2which may otherwise occur when the third device B3 is directly insertedinto the catheter 8 without using the guide pipe H. This also avoidsinconvenience of dragging the artificial blood vessel D or the devicesB1 and B2. As a result of this, the third device B3 can be introducedinto another branch without fail. Since the guide pipe H is arrangedwith its front tip h2 closer to the bifurcated position of the affectedportion than the front end of the catheter 8, it becomes easier to catchthe base end b3a by the catcher G. As a result of this, the rate ofsuccessful implanting can drastically be improved. This effect can alsobe obtained by using the J-shaped guide pipe F shown in FIG. 41.However, in this embodiment since not only the front end of the deviceB3 but also the base end b3a thereof is turned down, the base end b3acan be caught by the catcher G when the base end b3a projects out of thefront end h2 of the guide pipe H. Consequently, the position of the baseend b3a can freely be adjusted by manipulating the guide member b3x. Asa result of this, the device B3 can be caught with higher accuracy bythe catcher G. In addition, since the front end of the catcher G isloop-shaped and smooth, there is no danger of damaging tissues of thebody. Further, since the third device B3 is transported in the catheterK in a condition of being folded into a V-shape when it is to be takenafter caught, the base end b3a of the third device B3 can be taken outof the body without fail.

The device B (B1, B2 and B3) for transporting the artificial bloodvessel can be modified in each of the above-mentioned embodiments. Theside window formed in the tube 2, shown in FIGS. 54 through 58,comprises the first and the second opening holes 11H and 12H each spacedapart. The wire 3 pulled out of the tube 2 though the first opening hole11H is hooked by the strings 4 and then introduced into the tube 2through the second opening hole 12H. Thus arranged device B fortransporting the artificial blood vessel does not require a big openinglike the side window shown in FIG. 5. As a result of this, the tube 2around the side window is thick enough to prevent bending, therebyeffectively improving strength of the device B. In this case the crosssection of the device B may have a flat portion 2X between the openingholes 11H and 12H as shown in FIGS. 59 though 63. With the device Bhaving the flat portion 2X, the wire 3 pulled out of the first openinghole 11H can be inserted into the second opening hole 12H with the wire3 remaining relatively straight. Then the wire 3 can effectively beprevented from bending and it also avoids a case that the wire 3 failsto be pulled out of the tube 2. FIG. 64 shows another cross sectionhaving a concaved portion 2Y. As a further different modification shownin FIGS. 65 though 67, the tube 2 may comprise two tube elements 2A and2B each spaced apart, and a connector 2C for connecting the outercircumferences of both tube elements 2A and 2B. No matter whatarrangement the tube has, as far as the tube is strong enough as awhole, the device for transporting the artificial blood vessel cantransport artificial blood vessels appropriately. The tube comprisingtwo tube elements is especially effective for a tube having an extremelysmall diameter. If the tube of an extremely small diameter is providedwith a side window, the window occupies most of the tube, which mayweaken the strength of the tube. Consequently, the tube comprising twotube elements 2A and 2B can keep an appropriate strength as far as thematerial used for 2C is strong enough. The connector 2C may connect theinternal circumferences of two tube elements 2A and 2B as shown in FIGS.68 though 70. The cross section of the tube element 2A, 2B is notlimited to a circle as shown in FIG. 69, but may be flat or flat withpartial circle. In addition, the device B for transporting theartificial blood vessel shown in FIGS. 54 through 70 may not have astring 4. In this case, the device B can pull the artificial bloodvessel A effectively if the wire 3 is directly inserted into hookingmeans or a hole directly formed on the cover.

On the other hand, as a modification of the artificial blood vessel, itis effective to use the artificial blood vessel shown in FIG. 71. Theartificial blood vessel P has basically the same arrangement as that ofthe artificial blood vessel A shown in FIG. 1 except that an elasticthread 500 (for example, thread of urethane or the like) which canexpand or contract so as to shrink a length of the artificial bloodvessel P is embedded inside the tubular cover 7 along a specifiedgeneratrix. Thus arranged artificial blood vessel P can be transportedin the catheter 8 in compact when folded into a small size like theabove mentioned embodiment. In addition, since the artificial bloodvessel P is restored into a curved shape as shown in FIG. 71 whenreleased from the catheter 8 because the elastic thread 500 restrains apart of the artificial blood vessel P from restoring into a cylindricalshape, the artificial blood vessel P sticks to the blood vessel tightlywhen implanted into a curved affected portion such as a bowed portion ofaorta, thereby to prevent leakage. This effect can greatly be improvedif the artificial blood vessel P is used with an artificial blood vesselhaving a bellow portion.

It is also effective if a part or whole of the catheter 8 is made ofbellow, although not shown in figures. A catheter 8 of a simplecylindrical shape is not only easy to break but also difficult torestore if once broken, which may lead to stricture in a body. While thecatheter 8 made of bellow fits to a bent portion of the body easily withforming a natural curve, thereby to effectively avoid stricture in abody. Thus bellow-shaped catheter is suitable for transporting variouskinds of appliances in addition to artificial blood vessels.

The device B for transporting the artificial blood vessel used in theabove embodiments can be applied to pull various kinds of appliances inaddition to artificial blood vessels so as to introduce them into abody. The guide pipe H having valve 70 is also suitable for arranging anartificial blood vessel into a bifurcated portion having two or morebranches. For example, when an artificial blood vessel having branchesbifurcated from a trunk is used for the aorta of a neck, the trunk isarranged on the bowed portion of the aorta and the branch is introducedinto the carotid artery or the upper arm artery. In this case theartificial blood vessel can be implanted with ease and accuracy by usingthe guide pipe H. Further the valve 68 shown in FIGS. 51 and 52 can beapplied when a plurality of devices for transporting the artificialblood vessel are parallely introduced into a body without causingbleeding.

POSSIBLE APPLICATIONS IN INDUSTRY

As mentioned above, the appliance to be implanted in accordance with theinvention is valuable as an artificial blood vessel. It also can becollapsed into a small size to take a regular wavy shape having the samephase as a whole by means of the method of collapsing the appliance tobe implanted in accordance with the invention especially because ofsmooth movement of the intermediate wire rings. The method of using theappliance to be implanted in accordance with the invention makes itpossible to implant a Y-shaped appliance to be implanted into abifurcated portion of a human organ easily with non-operational method.

I claim:
 1. The method of collapsing the appliance to be implanted,comprising a front end wire ring, a rear end wire ring arranged facingto the front end wire ring, a tubular cover which connects the front endwire ring and the rear end wire ring, and a plurality of intermediatewire rings spaced apart from each other between the front end wire ringand the rear end wire ring, in which each of the wire rings is givenflexibly foldable elasticity, characterized by that the circumference ofsaid front end wire ring is divided at dividing points into four or aneven number over four segments, that hooking means are formed for afront pull string to be passed through at every other dividing point andthat the circumferences of the intermediate wire rings are fixed to thetubular cover by suturing or with adhesive at positions which correspondto midpoints between each adjacent two of the dividing points on thefront end wire ring, and that the method comprises the steps of: foldingsaid front end wire ring into a wavy shape with the dividing points eachof which is provided with a hooking means forming forwardly directedpeaks and the other dividing points forming bottoms of forwardlydirected valleys, folding the intermediate wire rings and the rear endwire ring each into a wavy shape aligned with that of the front end wirering, and inserting the whole appliance to be implanted into a catheter.2. The method of collapsing the appliance to be implanted, described inclaim 1 and characterized by that the whole appliance to be implanted ispicked up by forceps along a generatrix which passes two points facingeach other on the front end wire ring and each of which is provided witha hooking means, that the appliance to be implanted is inserted togetherwith the forceps into a funneled tube from a big portion of the funneledtube to a small portion thereof, and that the forceps are pulled out ofthe funneled tube.
 3. The method of collapsing the appliance to beimplanted, described in claim 2 and characterized by that the forcepsare provided with serrate engaging members which lessens a slidingresistance between the appliance to be implanted and the forceps towardthe direction opposite that of insertion.
 4. The method of collapsingthe appliance to be implanted, described in claim 1 and characterized bythat a pair of stings each of which has a loop at a tip thereof, areprovided for each of the wire rings respectively, that the strings areengaged with either one of said wire rings or the tubular cover atpositions on the circumference of each wire ring which correspond tomidpoints between two adjacent dividing points on the front end wirering, one of the strings is wound around the wire ring clockwise untilthe one string reaches half way around the wire ring while the otherstring is wound around the wire ring counterclockwise until it reacheshalf way around the wire ring, that a retaining rod is passed throughthe part at which each of the loops overlaps, and each of the strings istied to each other so as to keep each of the wire rings in a collapsedcondition.
 5. The method of collapsing the appliance to be implanted,described in claim 4 and characterized by that said retaining rodcomprises a tube and a wire which is inserted into and passed throughsaid tube and that after each of the wire rings is kept in a collapsedcondition the tube is pulled out so as to keep the collapsed conditionby the wire alone.
 6. The method of collapsing the appliance to beimplanted, described in claim 1 and characterized by that the applianceis collapsed into a small size by inserting it into a funneled tube froma big portion of the funneled tube toward a small portion thereof, thatthe appliance has previously been contained in a pipe member having adiameter which is bigger than that of the small portion of the funneledtube and smaller than that of the big portion of the funneled tube.